Method, apparatus and system for heating a body of fluid located outdoors

ABSTRACT

A method, apparatus and system are provided for heating fluids using a waste heat recovery arrangement adapted for application to existing heat exchange systems that generate waste heat and/or heated exhaust gases. The method, apparatus and system utilize the heater control arrangement of the existing heat exchange system to control the heating of the fluid and a pumping arrangement, for example, a hydrokinetic pumping arrangement, to circulate the fluid to be heated from a location outdoors to the heat exchange system.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention generally relates to a method, apparatus and system for heating a body of fluid located outdoors using a waste heat recovery arrangement adapted for application to existing heat exchange systems that generate waste heat and/or heated exhaust gases; and, more particularly to such a method, apparatus and system wherein the heater control arrangement of the existing heat exchange system is utilized to control the heating of the fluid and a pumping arrangement, for example, a hydrokinetic pumping arrangement, is used to circulate the fluid to be heated.

[0003] 2. Background of the Invention

[0004] Home heat exchange systems, such as air furnaces and hot water heaters, burn combustible mixtures, particularly hydrocarbon fuels and atmosphere oxygen, that require exhaust flues to vent the products of combustion and assure that carbon monoxide and other toxic gases do not accumulate in the home to present a health or safety hazard. Studies have indicated that a significant percentage of the heat from home heat exchange systems, as well as fireplaces and stoves, is lost through the escape of hot flue gases up the chimney.

[0005] In order to capture some of the heat lost up the flue it has been suggested to position heat exchanger(s) within the flue, which circulate a heat absorbing liquid, for example, water, there-through. The heated water can be directed to a hot water tank of the home hot water heater as a supplement to normal hot water generation, used in a hot water radiator to provide supplemental heat or used to provide supplemental heat to an air furnace. Although such prior art systems are partially successful in capturing some of the otherwise lost heat of the furnace, they are relatively complex, requiring extensive control arrangements with values and heat sensor as well as pumps to control the circulation of the fluid to the heat exchangers.

[0006] A typical example of such a prior art arrangement is disclosed by U.S. Pat. No. 4,401,261 to Brown which relates to a flue gas heat recovery apparatus employed with a system of appliances such as a gas furnace and hot water heater, each having separate exhaust gas flues. The apparatus includes a gas-to-liquid heat exchanger in thermal communication with the two flues to simultaneously extract heat therefrom and a liquid-to-gas heat exchanger disposed within the furnace cold air return duct. A pump circulates water between the exchangers in response to a control signal to employ the recovered heat to preheat the cold air entering the furnace through the cold air return duct. A hysteretic control circuit monitors exhaust gas temperature and provides for system operation between high and low gas temperature limits. In the preferred embodiment of the invention, a furnace blower override feature is employed to energize the blower during periods of pump operation.

[0007] While operationally effective, such prior art devices are expensive to manufacture, install and maintain. In addition, pumps, valves and controllers make such arrangements complex and subject to malfunction, increased maintenance and operation costs. Moreover, such arrangements are not adapted to provide heat to bodies of water located outdoors during the cooler months of the year to prevent freezing or maintain a minimum desired temperature.

SUMMARY OF THE INVENTION

[0008] Accordingly, it is an object of the present invention to provide a method, apparatus and system for heating a fluid using waste heat from an existing heat exchange system that overcomes the deficiencies of the prior art.

[0009] Another object of the present invention is to provide a method, apparatus and system for heating a fluid that eliminates the need for expensive moving parts or complicated control arrangements.

[0010] A further object of the present invention is to provide a method, apparatus and system for heating a fluid wherein a pumping arrangement, for example, a hydrokinetic pumping arrangement, is used to continuously circulate the fluid to be heated thereby eliminating the need for costly and complex valving arrangement and valve controllers.

[0011] Still another object of the present invention is to provide a method, apparatus and system for heating a fluid that eliminates the need for a dedicated heater control arrangement to control the heating of the fluid by using the heater control arrangement of the existing heat exchange system to control the heating of the fluid.

[0012] Yet another object of the present invention is to provide a method, apparatus and system for heating fluid that is easily retrofitted to existing heat exchange systems that exhaust heated fluids.

[0013] A further object of the present invention is to provide a method, apparatus and system for heating fluid that is very cost effective to operating and inexpensive to install and maintain.

[0014] The present invention can be advantageously used to heat bodies of water positioned outside during cold weather. In that regard, bodies of water, such swimming pools, hot tubs, fountains, fish ponds, outdoor watering containers (for plants and/or animals) and the like, are often situated near and around building structures, for example, such as homes, apartment buildings, barns, office builds and the like, that have existing heat exchange systems, such as air furnaces and water heaters, that exhaust hot gases via a flue. The heating of such outdoor bodies of water is desirable because, in some climates, the outside temperatures get so low that these bodies of water freeze during the winter months. Since water expands when it freezes, it can damage the structure of a fountain, swimming pool or spa unless special and expensive precautions are taken. In addition, freezing weather can kill many species of fish that are desirable to have in a fishpond, such as tropical fish, and make watering containers and fountains unusable.

[0015] In addition to the foregoing, the present invention advantageously eliminates the need for a dedicated heater control arrangement for controlling the heating of the fluid by using the heater control of the existing heat exchange system to control the heating of the fluid. For example, if the existing heat exchange system is an air furnace of a residential structure, such a home or the like, the operation of the air furnace is controlled by a thermostatic heater control arrangement that turns the furnace on and off as required to maintain a steady state temperature within the home during the cooler months of the year. Thus, the waste heat (for example) hot combustion products exhausted via the existing heater's flue) is only intermittently available to heat the fluid circulating through the heat exchanger and surprisingly provides adequate heating of the fluid for the envisioned applications of the present invention while also preventing the fluid from become too hot. This not only eliminates cost and complexity in the various embodiments of the present invention, but also unexpectedly provides a control arrangement which adequately heats a body of water located outdoors during cold weather to prevent freezing as well as maintain a fishpond at an adequate temperature in many climates to ensure the survival of topical fish during cold weather.

[0016] It should also be noted that the present invention is not reliant on existing heat exchange systems that only operate during cold or cool weather, such as an air furnace. Air conditioners generate considerable waste heat and water heaters operate all year round, i.e., without regard to the outdoor temperature. Thus, depending on the requirements for the use of the fluid to be heated, a variety of different existing heating arrangements are available and can be employed to tailor the present invention to needs of such requirements.

[0017] Furthermore, the use of a continuous pumping arrangement, such as, for example, a hydrokinetic pumping arrangement that constantly circulates the fluid to be heated between the heat exchanger and the body of fluid to be heated by waste heat from an existing heat exchange systems that operates intermittently to maintain a steady state temperature or temperature range, eliminates the need for a complex arrangement of valves and associated valve controllers thereby reducing cost, complexity and providing a simple yet effective arrangement for heating a fluid in an inexpensive manner.

[0018] To accomplish these and other objects as well as advantageous features of the present invention, the present invention, according to one embodiment thereof, is an apparatus for heating a fluid comprising: a waste heat recovery arrangement having a heat exchanger for extracting waste heat generated by an existing heat exchange system having a heater control for maintaining a steady state, a container located outdoors for containing the fluid to be heated; and a continuous pumping arrangement for constantly circulating the fluid to be heat through the heat exchanger of the waste heat recovery arrangement.

[0019] Further, the present invention includes a system for heating a fluid that comprises, according to one embodiment thereof: an existing heat exchange system that generates waste heat and has a heater control for maintaining a steady state temperature or temperature range; a waste heat recovery arrangement having a heat exchanger at the existing heat exchange system for extracting the waste heat generated by the existing heat exchange system, a container located outdoors for containing the fluid to be heated; and a continuous pumping arrangement for continuously circulating the fluid to be heat through the heat exchanger of the waste heat recovery arrangement.

[0020] The present invention also includes a method of heating a fluid that comprises, according to one embodiment, the steps of: 1) heating a body of fluid located outdoors using a waste heat recovery arrangement for extracting waste heat generated by an existing heat exchange system having a heater control for maintaining a steady state temperature or temperature range; and 2) continuously circulate the fluid between the waste heat recovery arrangement and the body of fluid located outdoors.

BRIEF DESCRIPTION OF THE DRAWING

[0021]FIG. 1 illustrates a known arrangement of existing heat exchange systems;

[0022]FIG. 2 schematically illustrates one embodiment of the apparatus of the present invention;

[0023]FIG. 3 is a cross-sectional view illustrating an alternative embodiment of the heat exchanger;

[0024]FIG. 4 is a cross-sectional view illustrating an alternative embodiment of the hydrokinetic pumping arrangement;

[0025]FIG. 5 illustrates one embodiment of the system of the present invention;

[0026]FIG. 6 is a block diagram illustrating the method of the present invention;

[0027]FIG. 7 is graph illustrating the heating characteristics and conditions for Example 1; and

[0028]FIGS. 8-12 illustrate further embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0029] Referring to FIG. 1, a known arrangement of existing heat exchange systems for use in a dwelling or building is illustrate, generally indicated at 11, comprising, for example, a water heater 13 and an air furnace 15, that are found, for example, in building structures, such as houses, apartment houses, office building, garages, barns or the like. Within the water heater 13 is a vessel (not shown) containing water to be heated by a heater (not shown) that generates waste heat, for example, in the form of heated exhaust gases from combustion, that are directed out of the building structure via a flue 17. The air furnace 15 similarly has a heater (not shown) for heating cold air conducted through the air furnace 17 that generates waste heat in the form of, for example, heated exhaust gases that are directed out the building structure via flue 19.

[0030] Each existing heat exchange system 13, 15 preferably has a controller 20 that controls the operation of the heat exchange system. For example, the controller 20 for the water heater 13 is a thermostat that controls the burner of the heater 13 to maintain the water temperature of the heater 13 at a predetermined temperature or within a desired temperature range. Similarly, the controller 20 for the air furnace 15 comprises, for example, a thermostatic control that operates to the burner of the furnace 15 to maintain a given air temperature within the building. It should be understood that existing heat exchange systems other than those specifically discussed above are envisioned for use in accordance with the teaching of the present invention. In that regard, any existing heat exchange system that generates waste heat that can be used by the present invention, including, but not limited to refrigeration systems that exhaust large quantities of waste heat.

[0031] Referring to FIG. 2, one embodiment of an apparatus for heating a fluid, generally indicated at 21, is illustrated in accordance with the teachings of the present invention. The apparatus 21 comprises a waste heat recovery arrangement, generally indicated at 23, having a heat exchanger 25 for extracting waste heat generated by an existing heat exchange system. The waste heat recovery arrangement is, for example, an exhaust gas recovery arrangement wherein the heat exchange is adapted for insertion into heated exhaust gases A generated by the existing heat exchange system (not shown). The apparatus 21 also includes a pumping arrangement, for example, a hydrokinetic pumping arrangement generally indicated at 27, for continuously circulating the fluid to be heat between the heat exchanger 25 of the wasted heat recovery arrangement 23 and a vessel of fluid 35 located outdoors. Although a hydrokinetic pumping arrangement is shown, any suitable pumping arrangement, such as an electric pump that operates continuously, is acceptable. The heat exchanger 25 is positioned, for example, adjacent the heating unit (not shown) of the existing heat exchange system, at the exhaust port (not shown) of the heating unit leading to a flue 33 or in the flue 33 that exhausts the waste heat and/or exhaust gases. Conduits 29, 31 convey the fluid to be heated between the heat exchanger 25 and the pumping arrangement 27. During the operation of the present invention, the pumping arrangement 23 constantly circulates the fluid to be heated through the heat exchanger 25.

[0032] The pumping arrangement 27 comprises, according to one embodiment of the present invention, a hydrokinetic pumping arrangement located at a container 35 located outdoors that is divided, for example, by a weir 37 to create an upper body of fluid 39 and lower body of water 41. In a classic siphon arrangement, the open end of conduit 29 inserted into upper body of water 39 is position higher than the open end of conduit 31 inserted into lower body of water 41. Due to the unequal heights of conduits 29, 31 respectively inserted into bodies of water 39, 41, fluid is drawn out of upper body of water 39 by the force of atmospheric pressure exerted on the bodies of water 39, 41, circulated though the heat exchanger 25 and returned to the lower body of water 41. In order to maintain the siphon, a pump 43 is provided for circulating the fluid returned to the lower body of water 41 back to the upper body of water 39 to preserve the difference between the levels of fluid in the upper and lower bodies of water 39, 41.

[0033]FIGS. 3 and 4 illustrate alternative embodiments of the heat exchanger 25 and the hydrokinetic pumping arrangement 27, respectively. Referring to FIG. 3, the heat exchanger 25 comprises a plurality of coils 47 positioned in a flue 33 for exhausting waste heat or heated exhaust gases from an existing heat exchange system (not shown). Because there are oftentimes regulations and building codes that dictate the required minimum diameter d of the flue 33, it is preferable to position the coils 47 in such a manner so as to prevent obstruction of the flow of gases via the flue 33 and maintain the minimum required diameter d of the flue 33. Therefore, according to this embodiment of the heat exchanger 25, the coils 47 are position at a widened flue segment 45 having a diameter D large enough to maintain an unobstructed diameter d and position the coils 47 outside of the minimum diameter d of the flue 33.

[0034] Referring to FIG. 4, an alternative embodiment of the hydrokinetic pumping arrangement 25 is shown wherein the vessel 35 is divided by a hollow structure, for example, a tube 37, to create an upper body of water 39 and lower body of water 41. In a classic siphon arrangement, the open end of conduit 29 inserted into upper body of water 39 is position higher than the open end of conduit 31 inserted into lower body of water 41. Due to the unequal heights of conduits 29, 31 respectively inserted into bodies of water 39, 41, fluid is drawn out of upper body of water 39 by the force of atmospheric pressure exerted on the bodies of water 39, 41, circulated though the heat exchanger 25 and returned to the lower body of water 41. In order to maintain the siphon, a pump 43 for circulating the fluid returned to the lower body of water 41 back to the upper body of water 39 and preserve the difference between the levels of fluid in the upper and lower bodies of water 39, 41 is provided.

[0035] It should be noted that the container 35, according to one embodiment of the present invention, comprises a body of water positioned outside in the weather, for example, a swimming pool, hot tub, fountain, fishpond, landscape pond, outdoor watering container (for plants and/or animals) and the like. Such outside bodies of water are often situated near and around building structures, for example, such as homes, apartment buildings, barns, office builds and the like, that have existing heat exchange systems, such as air furnaces and water heaters, that exhaust hot gases via a flue. The heating of such outdoor bodies of water is desirable to prevent freezing of the water when the outside temperatures get below freezing or to maintain a minimum desired temperature of the water, for example, if the body of water is a fish pond or the like. Since water expands when it freezes, it can damage the structure of a fountain, swimming pool or spa unless special and expensive precautions are taken. In addition, freezing weather can kill many species of fish that are desirable to have in a fishpond, such as tropical fish, if the temperature of water gets too low and make watering containers and fountains unusable.

[0036] Referring to FIG. 5, one embodiment of a system for heating a fluid, generally indicated at 49, is shown in accordance with the teachings of the present invention. The system 49 comprises an existing heat exchange system 51 that generates waste heat and/or heated exhaust gases and preferably has a controller 20 which controls the operation of the heat exchange system 51 so as to maintain a desired steady state, for example, habitable temperatures within a building structure such as a home or office building and the like.

[0037] Positioned at the heat exchange system 51 is a waste heat recovery system, generally indicated at 53, that includes a heat exchanger 55 inserted, for example, into heated exhaust gases generated by the existing heat exchange system 49. In the embodiment illustrated by FIG. 5, the heat exchanger 55 is position in a flue 57 of the existing heat exchange system 51, however, the heat exchanger 55 can be positioned in any suitable location at the existing heat exchange system 51 that provides adequate heat, such as at the exhaust port of the heater (not shown) of the existing heat exchange system 51 that leads to the flue 57. A pumping arrangement, for example, an electric pump or a hydrokinetic pumping arrangement, generally indicated 59, is provided for continuously circulating a fluid to be heat 61 through the heat exchanger 55 of the waste heat recovery arrangement 53.

[0038]FIG. 6 is a block diagram illustrating the method of the present invention. According to one embodiment the method comprises the steps of: A method of heating a fluid comprising the steps of: 1) locating a body of fluid outdoors; 2) heating the body of fluid by continuously circulating the fluid between a waste heat recovery system for extracting heat from waste heat generated by an existing heat exchange system and the body of fluid; and 3) using a pumping arrangement to continuously circulate the fluid between the body of fluid and the heat exchanger. According to a further embodiment of the present invention, the method further comprises the step of using a hydrokinetic pumping arrangement to continuously circulate the fluid to be heated. In yet another embodiment of the method, the waste heat from the existing heat exchange system is generated in the form of heated exhaust gases and the waste heat recovery system is an exhaust gas heat recovery arrangement for placement in the heated exhaust gases of the existing heat exchange system. In a further embodiment, the method further comprises the step of using the controller that controls the operation of the existing heat exchange system to control the heating of the fluid.

EXAMPLE 1

[0039] The present invention was used to heat a fishpond populated with tropical fish and located in Marietta, Ga. USA during the winter of 2002-2003. The fishpond was located in the ground and contained approximately 400 gallons of water and was divided into upper and lower sections by a weir that formed a waterfall of approximately 12 inches. A small electric pump (Askol brand Powerhead 301 pump) was used to circulate the water between the upper and lower sections of the pond. The heat exchanger of the present invention, located just above the burners of a 50,000 BTU air furnace, was in fluid communication with the pond via ¾″ diameter pipes. When the pipes are located outside and above ground, insulating the pipes helps to minimize loss of heat from the water being circulated there through. The temperature of the water in the pond was maintained at an average temperature of approximately 71.17 degrees F. despite an average outside temperature of about 49.0 degrees F. A tarp was position adjacent and above the fishpond in a lean-to fashion to keep precipitation out of the pond. FIG. 7 shows the heating characteristics and conditions for Example 1 wherein “Heater” refers to the temperature of the water exiting the heat exchanger into the pond; “Pond” refers to the temperature of the water in the pond; “Furnace” refers to the thermostat setting of the furnace; and “Outdoor” refers to the outside air temperature.

EXAMPLE 2

[0040] The present invention was used to heat a watering trough located in Marietta, Ga. USA during the winter of 2002-2003. The watering trough was located above ground in a metal container and held approximately 60 gallons of water. The watering trough was divided into upper and lower sections by a hollow tube similar to the arrangement illustrated by FIG. 4 so as to form a water column of approximately 12 inches. A small electric pump (Askol brand Powerhead 301 pump) was used to circulate the water between the upper and lower sections of the trough. The heat exchanger was located in the exhaust flue such as shown by FIG. 3 of a 50,000 BTU home heating air furnace that had its thermostat set at 70 degrees F. Fluid communication between the water in the trough and the heat exchanger was established via ¾ diameter pipes. When the pipes are located outside and above ground, insulating the pipes helps to minimize loss of heat from the water being circulated there through. The water in the watering trough was maintained in a fluid state even though the ambient temperature dipped below freezing. Water discharged from the heat exchanger into the watering trough was approximately 82 degrees F. The chart below shows the conditions of Example 2 and compares the temperature of an unheated water trough and a water trough heated in accordance with the teachings of the present invention Heated Date Time Outside T Unheated Trough T Trough T Nov. 25, 2002  9 AM 52 F 46 F 66 F Nov. 26, 2002 10 AM 45 F 43 F 64 F Nov. 27, 2002  9 AM 48 F 48 F 60 F Nov. 28, 2002  9 AM 26 F 31 F 62 F Nov. 29, 2002  9 AM 28 F 31 F 60 F Nov. 30, 2002  9 AM 27 F 33 F 60 F Dec. 1, 2002  9 AM 26 F 32 F 60 F Dec. 2, 2002  9 AM 25 F 28 F 63 F Dec. 3, 2002  9 AM 30 F 32 F 60 F Dec. 4, 2002  9 AM 32 F 34 F 62 F Dec. 5, 2002  9 AM 36 F 32 F 64 F Dec. 6, 2002  9 AM 30 F 32 F 60 F Jan. 7, 2002  9 AM 26 F 32 F 60 F Jan. 8, 2003 11 AM 30 F 33 F 60 F Jan. 9, 2003  9 AM 28 F 33 F 60 F

[0041]FIG. 8 illustrates a further embodiment of the present invention, as applied, for example, to a body of water 63 located outside having an elevated portion, such as a pond having a waterfall, wherein the pond pump motor 65, typically used to drive the waterfall, is used to circulate the water from the pond directly to and through the heater exchanger 67 of the waste heat recovery arrangement 69. The pond pump motor 65 comprises, for example, an engine driven pump, such an electric pump, which operate continuously when turned on, such as for example, an Askol brand Powerhead 301 pump.

[0042]FIG. 9 illustrates yet another embodiment of the present invention, as applied, for example, to a body of water 63 located outside having, for example, an elevated portion, such as a pond having a waterfall, wherein the pond pump motor 65, typically used to drive the waterfall, is used to circulate the water through the heater exchanger 67 of the waste heat recovery arrangement 69. However, in the embodiment of FIG. 9, a cut off valve 71, that is adapted to incrementally shut off the flow of fluid there-through, is provided downstream from a t-connector to regulate or allow some amount of the water to be pumped to the heat exchanger 67 from the pump 65 and most of the water to be diverted straight to the elevated portion of the pond 63.

[0043]FIG. 10 illustrates still a further embodiment of the present invention, as applied, for example, to a body of water 63 located outside having, for example, an elevated portion, such as a pond having a waterfall, wherein the pond pump motor 65, typically used to drive the waterfall, is used to circulate the water through the heater exchanger 67 of the waste heat recovery arrangement 69. In this embodiment, water circulation to the heat exchanger 67 depends on a hydrokinetic pumping arrangement, such as a siphon, but can also get support from the pond pump 65 so as to establish the siphon at start-up or circulate more water through the heat exchanger 67 than the siphon is capable of providing. To accomplish this a cut-off/split valve 75 is provided as shown. In this arrangement, it is possible to circulate the water just using the siphon by closing valve 75 completely or supplement the water being circulated to the heat exchanger 67 by opening the valve 75 incrementally up to the full open position in which case the siphon is fully supported by the pump 65.

[0044]FIG. 11 illustrates still a further embodiment of the present invention, as applied, for example, to a body of water 63 located outside wherein an engine driven pump 73, which operate continuously when turned on, such as for example, an electric Askol brand Powerhead 301 pump, is used to directly circulate the water from the body of water 63, through the heater exchanger 67 of the waste heat recovery arrangement 69 and back to the body of water 63. In the embodiment of FIG. 11, the pump 73 is illustrated as being located, for example, outside of the body of water 63 however, the pump 73 can also be located in the body of water 63. The body of water 63 does not necessarily have an elevated portion in this embodiment, but it may. If the body of water 63 has an elevated portion, such as, for example, a pond with a waterfall, a pond pump (not shown) can also be included to drive the waterfall.

[0045]FIG. 12 illustrates still another embodiment of the present invention, as applied, for example, to a body of water 63 located outside having, for example, an elevated portion, such as a pond having a waterfall, wherein the pond pump motor 65, typically used to drive the waterfall, is used to circulate the water through the heater exchanger 67 of the waste heat recovery arrangement 69. In this embodiment, an engine driven pump 77, which operates, for example, continuously when turned on, such as for example, an electric Askol brand Powerhead 301 pump, is used to support or, supplement water flow provided by the siphon as needed. In the embodiment of FIG. 12, the pump 77 is illustrated as being located, for example, outside of the body of water 63 however, the pump 77 can also be located in the body of water 63.

[0046] In all the Examples above, ¾″ pipe was employed as the conduit for transporting the fluid through the invention.

[0047] As noted, the present invention utilizes existing heat exchange systems such the household air furnace or water heater which each have control arrangements for maintaining a steady state temperature. In the case of a household air furnace, the colder it is outside, the more the air furnace must heat the interior of the house in order to maintain a steady state temperature, such as 70 degrees F. The more the air furnace works, the more waste heat is generated, and since the fluid to be heated by the present invention is continuously circulated between the body of fluid situated outside and the heat exchanger position in the exhaust gas of the furnace, the more heat is imparted to the fluid, thereby compensating for the lower outdoor temperatures.

[0048] The inventor of the present invention has found that a circulation rate in the range of between about 1 gallon/minute to about 4 gallons/minute provides adequate heating of the fluid for the purposes disclosed in the present application. In that regard, the slower the circulation rate, the more heat is imparted to the fluid, i.e., a higher delta temperature is seen between the temperature of the fluid going into the heat exchanger as opposed to the temperature of the fluid exiting the heat exchanger of the waste heat recovery arrangement. However, the rate of circulation must also be balance with consideration of the volume of fluid in the container. For example, with an in-ground outdoor pond of 400 gallons, it was found that the in order to keep the pond at a sufficient temperature to maintain tropical fish, the entire 400 gallons needed to circulated approximately every two hours, i.e., approximately 3.3 gallons per minute whereas a 60 gallon watering trough located in a metal container positioned above ground required a circulation rate of about 2.0 gallons/minute. In addition to the foregoing consideration, the amount of fluid in the heat exchanger 25 located in the heated exhaust gases must also be considered in addition to the rate at which the fluid flows through the invention. In that regard, the inventor has found that for the parameters discussed above, between about 1.0 to 1.8 gallons of fluid should be in the heat exchanger 25 available for absorbing heat during operation of the present invention. If the diameter of the conduit comprising the heat exchanger 25 is about ¾″, then the length of conduit making up the heat exchanger 25 is about 30 to 50 feet.

[0049] Although the present invention has been described in terms of specific exemplary embodiments, it will be appreciated that various modifications and alterations might be made by those skilled in the art without departing from the spirit and scope of the invention as specified in the following claims. 

What is claimed is:
 1. An apparatus for heating a fluid comprising: a waste heat recovery arrangement for placement at an existing heat exchange system that generates waste heat, the waste heat recovery arrangement having a heat exchanger for extracting the waste heat generated by the existing heat exchange system; a container for containing the fluid wherein the container is located outdoors; and a pumping arrangement for circulating the fluid to be heat between the heat exchanger of the waste heat recovery arrangement and the container of fluid.
 2. An apparatus according to claim 1, wherein the existing heat exchange system generates waste heat in the form of heated exhaust gases and the waste heat recovery arrangement comprises an exhaust gas heat recovery arrangement for placement in the heated exhaust gases of the existing heat exchange system.
 3. An apparatus according to claim 3, wherein the existing heat exchange system comprises at least one of a hot water heater, a fireplace, air conditioner and an air furnace.
 4. An apparatus according to claim 1, wherein the existing heat exchange system includes a controller that controls the operation of the existing heat exchange system to maintain a desired steady state.
 5. An apparatus according to claim 1, wherein the pumping arrangement comprises at least one of an engine driven pump and a hydrokinetic pumping arrangement having: a divider for dividing the container into an upper and lower bodies of fluid; first and second conduits respective inserted into the upper and lower bodies of fluid for connecting the heat exchanger in fluid communication with the upper and lower bodies of fluid; a siphon arrangement wherein an open end of the first conduit inserted into the upper body of water is positioned higher than an open end of the second conduit inserted into the lower body so that due to the unequal heights of the open ends of the first and second conduits respectively inserted into upper and lower bodies of fluid, fluid is drawn out of upper body by the force of atmospheric pressure exerted on the upper and lower bodies, circulated though the heat exchanger and returned to the lower body of water; and. a pump for circulating fluid returned to the lower body of water back to the upper body of water to preserve the difference between the levels of fluid in the upper and lower bodies of water.
 6. An apparatus according to claim 5, wherein the divider comprises a weir that divides the container into upper and lower bodies.
 7. An apparatus according to claim 6, wherein the divider comprises a hollow structure that divides the container into upper and lower bodies.
 8. An apparatus according to claim 1, wherein the container is at least one of a pond, a fishpond, a watering trough, a swimming pool and a spa.
 9. A system for heating a fluid comprising: an existing heat exchange system that generates waste heat; a waste heat recovery arrangement having a heat exchanger at the existing heat exchange system for extracting heat from the waste heat from the existing heat exchange system; a container for containing the fluid, wherein the container is located outdoors; and a pumping arrangement for circulating the fluid to be heat between the heat exchanger and the container of fluid.
 10. A system according to claim 9, wherein the existing heat exchange system generates waste heat in the form of heated exhaust gases and the waste heat recovery arrangement comprises an exhaust gas heat recovery arrangement for placement in the heated exhaust gases of the existing heat exchange system.
 11. A system according to claim 10, wherein the existing heat exchange system comprises at least one of a hot water heater, a fireplace air conditioner, and an air furnace.
 12. A system according to claim 9, wherein the existing heat exchange system includes a controller that controls the operation of the existing heat exchange system to maintain a desired steady state.
 13. A system according to claim 9, wherein the pumping arrangement comprises at least one of an engine driven pump and a hydrokinetic pumping arrangement having: a divider for dividing the container into an upper and lower bodies of fluid; first and second conduits respective inserted into the upper and lower bodies of fluid and for placing the heat exchanger in fluid communication with the upper and lower bodies of fluid; a siphon arrangement wherein an open end of the first conduit inserted into the upper body of water is positioned higher than an open end of the second conduit inserted into the lower body so that due to the unequal heights of the open ends of the first and second conduits respectively inserted into upper and lower bodies of fluid, the fluid is drawn out of upper body by the force of atmospheric pressure exerted on the upper and lower bodies, circulated though the heat exchanger and returned to the lower body of water; and. a pump for circulating fluid returned to the lower body of water back to the upper body of water to preserve a difference between the levels of fluid in the upper and lower bodies of water.
 14. An apparatus according to claim 13, wherein the divider is a weir that divides the container into upper and lower bodies.
 15. An apparatus according to claim 13, wherein the divider is a hollow structure that divides the container into upper and lower bodies.
 16. An apparatus according to claim 9, wherein the container is at least one of a pond, a fishpond, a watering trough, a swimming pool and a spa.
 17. A method of heating a fluid comprising the steps of: locating a body of fluid outdoors; heating the body of fluid by continuously circulating the fluid between a waste heat recovery system for extracting heat from waste heat generated by an existing heat exchange system and the body of fluid; and pumping the fluid so as to continuously circulate the fluid between the body of fluid and the heat exchanger.
 18. A method according to claim 17, wherein the step of pumping further comprising the using at least one of an engine driven pump and a hydrokinetic pumping arrangement.
 19. A method according to claim 17 wherein the waste heat is generated in the form of heated exhaust gases and the waste heat recovery system comprises an exhaust gas heat recovery arrangement for placement in the heated exhaust gases of the existing heat exchange system.
 20. A method according to claim 3, wherein the existing heat exchange system includes a controller that controls the operation of the existing heat exchange system to maintain a desired steady state. 